Star profile
Achernar
Alpha Eridani · Eridanus
Variable starWhat is Achernar
Achernar marks the end of Eridanus, the celestial river, and its Arabic name «akhir an-nahr» means just that: «the river's end». It is a blue star spinning so fast that it visibly flattens at the poles, a luminous spinning top 139 light-years away. The light arriving tonight set out in the last decade of the nineteenth century, when gas lamps still burned in many European cities.
Where it is and when to see it
Achernar lies in the southern celestial hemisphere. It is one of the brightest stars in the sky: visible even from a city. Its best month of the year is September, when it culminates around midnight.
- From London it never rises above the horizon.
- From New York it never rises above the horizon.
- From Sydney it never sets and culminates about 67° up.
It can be seen from anywhere south of 33° N.
It is the brightest of the 129 stars of Eridanus in our catalogue, which makes it the best starting point for finding your way around the constellation.
The light you see today left it about 140 years ago.
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Astronomical data for Achernar
- Constellation
- Eridanus
- Apparent magnitude
- 0.45
- Distance
- 139.5 light years
- Coordinates (J2000)
- RA 24.428° · Dec -57.237°
- Catalogue
- HIP 7588 · HD 10144
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Other stars in Eridanus
Eridanus has 129 stars in Stelvia's catalogue. Here are a few of them.
- CursaBeta Eridani2.78
- AcamarTheta 1 Eridani2.88
- ZaurakGamma Eridani2.97
- RanaDelta Eridani3.52
- Upsilon 4 Eridani3.55
- Phi Eridani3.56
- Chi Eridani3.69
- Tau 4 Eridani3.70